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Measurements of the $B^+$, $B^0$, $B_s^0$ meson and $\Lambda_b^0$ baryon lifetimes
/ LHCb collaboration
Measurements of $b$-hadron lifetimes are reported using $pp$ collision data, corresponding to an integrated luminosity of 1.0fb$^{-1}$, collected by the LHCb detector at a centre-of-mass energy of $7$Tev. Using the exclusive decays $B^+\to J/\psi K^+$, $B^0\to J/\psi K^*(892)^0$, $B^0\to J/\psi K^0_{\rm S}$, $\Lambda_b^0\to J/\psi \Lambda$ and $B^0_s\to J/\psi \phi$ the average decay times in these modes are measured to be $\tau_{B^+\to J/\psi K^+}$ = $1.637 \pm$ 0.004 $\pm$ 0.003 ps, $\tau_{B^0\to J/\psi K^*(892)^0}$ = $1.524 \pm$ 0.006 $\pm$ 0.004 ps, $\tau_{B^0\to J/\psi K^0_{\rm S}}$ = $1.499 \pm$ 0.013 $\pm$ 0.005 ps, $\tau_{\Lambda_b^0\to J/\psi \Lambda}$ = $1.415 \pm$ 0.027 $\pm$ 0.006 ps and $\tau_{B^0_s\to J/\psi \phi}$ = $1.480 \pm$ 0.011 $\pm$ 0.005 ps, where the first uncertainty is statistical and the second is systematic. [...]
arXiv:1402.2554; LHCB-PAPER-2013-065; CERN-PH-EP-2014-018; LHCB-PAPER-2013-065; CERN-PH-EP-2014-018.-
Geneva : CERN, 2014 - 26 p.
- Published in : JHEP 04 (2014) 114
Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint
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2.
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Observation of $B^+_c \rightarrow J/\psi D_s^+$ and $B^+_c \rightarrow J/\psi D_s^{*+}$ decays
/ LHCb Collaboration
The decays $B^+_c \rightarrow J/\psi D_s^+$ and $B^+_c \rightarrow J/\psi D_s^{*+}$ are observed for the first time using a dataset, corresponding to an integrated luminosity of 3$fb^{-1}$, collected by the LHCb experiment in proton-proton collisions at centre-of-mass energies of $\sqrt{s}$=7 and 8 TeV. The statistical significance for both signals is in excess of 9 standard deviations. [...]
arXiv:1304.4530; CERN-PH-EP-2013-051; LHCB-PAPER-2013-010; CERN-PH-EP-2013-051; LHCB-PAPER-2013-010.-
Geneva : CERN, 2013-06-28 - 10 p.
- Published in : Phys. Rev. D
APS Open Access article: PDF; Fulltext: PDF; Publisher’s Note: PDF; Related data file(s): ZIP; External link: Preprint
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3.
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Measurements of the branching fractions of $B^{+} \to p \bar{p} K^{+}$ decays
/ LHCb Collaboration
The branching fractions of the decay $B^{+} \to p \bar p K^{+}$ for different intermediate states are measured using data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb experiment. The total branching fraction, its charmless component $(M_{p\bar p} <2.85 $ $ GeV/c^{2})$ and the branching fractions via the resonant $c\bar c$ states $\eta_{c}(1S)$ and $\psi(2S)$ relative to the decay via a $J/\psi$ intermediate state are \begin{align*} \frac{{\mathcal B}(B^{+} \to p \bar p K^{+})_{total}}{{\mathcal B}(B^{+} \to J/\psi K^{+} \to p \bar p K^{+})}=& \, 4.91 \pm 0.19 \, {(\rm stat)} \pm 0.14 \, {(\rm syst)},\\ \frac{{\mathcal B}(B^{+} \to p \bar p K^{+})_{M_{p\bar p} <2.85 {GeV/}c^{2}}}{{\mathcal B}(B^{+} \to J/\psi K^{+} \to p \bar p K^{+})}=& \, 2.02 \pm 0.10 \, {(\rm stat)}\pm 0.08 \, {(\rm syst)},\\ \frac{{\mathcal B} (B^{+} \to \eta_{c}(1S) K^{+} \to p \bar p K^{+})}{{\mathcal B}(B^{+} \to J/\psi K^{+} \to p \bar p K^{+})} = & \, 0.578 \pm 0.035 \, {(\rm stat)} \pm 0.027 \, {(\rm syst)},\\ \frac{{\mathcal B} (B^{+} \to \psi(2S) K^{+} \to p \bar p K^{+})}{{\mathcal B}(B^{+} \to J/\psi K^{+} \to p \bar p K^{+})}=& \, 0.080 \pm 0.012 \, {(\rm stat)} \pm 0.009 \, {(\rm syst)}.\\ \end{align*} Upper limits on the $B^{+}$ branching fractions into the $\eta_{c}(2S)$ meson and into the charmonium-like states $X(3872)$ and $X(3915)$ are also obtained..
arXiv:1303.7133; LHCB-PAPER-2012-047; CERN-PH-EP-2013-040; LHCB-PAPER-2012-047; CERN-PH-EP-2013-040.-
Geneva : CERN, 2013-06-13 - 14 p.
- Published in : Eur. Phys. J. C 73 (2013) 2462
Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint
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4.
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Observation of the $B^0_{s}\to\psi{(2\mathrm{S})}\eta$ and $B^0_{(s)}\to\psi{(2\mathrm{S})}\pi^+\pi^-$ decays
/ LHCb Collaboration
First observations of the $B^0_s \rightarrow \psi(2S) \eta$, $B^0 \rightarrow \psi(2S) \pi^+ \pi^-$ and $B^0_s \rightarrow \psi(2S) \pi^+ \pi^-$ decays are made using a dataset corresponding to an integrated luminosity of 1.0 $fb^{-1}$ collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=7$ TeV. The ratios of the branching fractions of each of the $\psi(2S)$ modes with respect to the corresponding $J/\psi$ decays are \[ \frac{\mathcal{B}(B^0_s \rightarrow \psi(2S) \eta) }{\mathcal{B}(B^0_s \rightarrow J/\psi \eta)} =0.83\pm0.14\,(stat)\pm0.12\,(syst)\pm0.02\,(\mathcal{B}), \] \[ \frac{\mathcal{B}(B^0 \rightarrow \psi(2S) \pi^+ \pi^-)}{\mathcal{B}(B^0 \rightarrow J/\psi \pi^+ \pi^-)} =0.56\pm0.07\,(stat)\pm0.05\,(syst)\pm0.01\,(\mathcal{B}), \] \[ \frac{\mathcal{B}(B^0_s \rightarrow \psi(2S) \pi^+ \pi^-)}{\mathcal{B}(B^0_s \rightarrow J/\psi \pi^+ \pi^-)} =0.34\pm0.04\,(stat)\pm0.03\,(syst)\pm0.01\,(\mathcal{B}), \] where the third uncertainty corresponds to the uncertainties of the dilepton branching fractions of the $J/\psi$ and $\psi$(2S) meson decays..
arXiv:1302.6354; CERN-PH-EP-2013-024; LHCB-PAPER-2012-053; CERN-PH-EP-2013-024; LHCB-PAPER-2012-053.-
Geneva : CERN, 2013-06-21 - 16 p.
- Published in : Nucl. Phys. B 871 (2013) 403-419
APS published version, local copy: PDF; Elsevier Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint
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5.
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Measurements of $B_c^+$ production and mass with the $B_c^+ \to J/\psi \pi^+$ decay
/ LHCb Collaboration
Measurements of $B_c^+$ production and mass are performed with the decay mode $B_c^+ \to J/\psi \pi^+$ using 0.37 fb$^{-1}$ of data collected in $pp$ collisions at $\sqrt{s}=7$~TeV by the LHCb experiment. The ratio of the production cross-section times branching fraction between the $B_c^+ \to J/\psi \pi^+$ and the $B^+ \to J/\psi K^+$ decays is measured to be $(0.68 \pm 0.10\,({\rm stat.}) \pm 0.03\,({\rm syst.}) \pm 0.05\,({\rm lifetime}) )\%$ for $B_c^+$ and $B^+$ mesons with transverse momenta $p_{\rm T}>4~$GeV/$c$ and pseudorapidities $2.5<\eta<4.5$. [...]
arXiv:1209.5634; LHCB-PAPER-2012-028; CERN-PH-EP-2012-275; LHCB-PAPER-2012-028; CERN-PH-EP-2012-275.-
Geneva : CERN, 2012 - 15 p.
- Published in : Phys. Rev. Lett. 109 (2012) 232001
APS Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint
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6.
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Observation of the decay $B_c^+ \rightarrow J/\psi K^+ K^- \pi^+$
/ LHCb Collaboration
The decay $B_c^+ \rightarrow J/\psi K^+ K^- \pi^+$ is observed for the first time, using proton-proton collisions collected with the LHCb detector corresponding to an integrated luminosity of 3 fb$^{-1}$. A signal yield of 78$\pm$14 decays is reported with a significance of 6.2 standard deviations. [...]
arXiv:1309.0587; CERN-PH-EP-2013-165; LHCB-PAPER-2013-047; LHCB-PAPER-2013-047; CERN-PH-EP-2013-165.-
Geneva : CERN, 2013 - 16 p.
- Published in : JHEP 11 (2013) 094
Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint
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7.
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Measurement of the polarization amplitudes in $B^0 \to J/\psi K^{*}(892)^0$ decays
/ LHCb collaboration
An analysis of the decay $B^0 \to J/\psi K^{*}(892)^0$ is presented using data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected in $pp$ collisions at a centre-of-mass energy of 7TeV with the LHCb detector. The polarisation amplitudes and the corresponding phases are measured to be \[ \begin{array}{cclllllll} |A_{\parallel}|^2 &\;=\; & 0.227 &\pm & 0.004 & \text{(stat.)} &\pm & 0.011 & \text{(syst.)}, \\ |A_{\perp}|^2 &\;=\; & 0.201 &\pm & 0.004 & \text{(stat.)} &\pm & 0.008&\text{(syst.)},\\ \delta_{\parallel}\; \text{[rad]} &\;=\; & -2.94 &\pm & 0.02 &\text{(stat.)} &\pm &0.03&\text{(syst.)},\\ \delta_{\perp}\; \text{[rad]} &\;=\; & \phantom{-}2.94 &\pm & 0.02 &\text{(stat.)} &\pm &0.02&\text{(syst.)}.\\ \end{array} \] Comparing $B^0\to J/\psi K^{*}(892){^0}$ and $\overline{B}^0\to J/\psi \overline K^{*}(892){^0}$ decays, no evidence for direct CP violation is found..
arXiv:1307.2782; CERN-PH-EP-2013-104; LHCB-PAPER-2013-023; CERN-PH-EP-2013-104; LHCB-PAPER-2013-023.-
Geneva : CERN, 2013-09-03 - 12 p.
- Published in : Phys. Rev. D 88 (2013) 052002
APS Open Access article: PDF; Fulltext: PDF; Related data file(s): ZIP; External link: Preprint
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8.
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First observation of the decay $B_{c}^{+}\to J/\psi K^+$
/ LHCb collaboration
The decay $B_c^+\to J/\psi K^+$ is observed for the first time using a data sample, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb experiment in $pp$ collisions at a centre-of-mass energy of 7 TeV. A yield of 46$\pm12$ events is reported, with a significance of 5.0 standard deviations. [...]
arXiv:1306.6723; CERN-PH-EP-2013-106; LHCB-PAPER-2013-021; CERN-PH-EP-2013-106; LHCB-PAPER-2013-021.-
Geneva : CERN, 2013 - 14 p.
- Published in : JHEP 09 (2013) 075
Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint
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9.
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Exclusive J/$\psi$ and $\psi$(2S) production in $pp$ collisions at $\sqrt{s} = 7$ TeV
/ LHCb Collaboration
Exclusive $J/\psi$ and $\psi(2S)$ vector meson production has been observed in the dimuon channel using the LHCb detector. The cross-section times branching fractions to two muons with pseudorapidities between 2.0 and 4.5 are measured to be \begin{equation*} \sigma_{pp\rightarrow J/\psi (\rightarrow \mu^{+} \mu^{-})} (2.0 <\eta_{\mu^{\pm}}< 4.5) = 307 \pm 21 \pm 36~\text{pb}, \end{equation*} \begin{equation*} \sigma_{pp\rightarrow \psi(2S) (\rightarrow \mu^{+} \mu^{-})} (2.0 <\eta_{\mu^{\pm}}< 4.5) = 7.8 \pm 1.3 \pm 1.0~\text{pb}, \end{equation*} where the first uncertainties are statistical and the second are systematic. [...]
arXiv:1301.7084; CERN-PH-EP-2013-005; LHCB-PAPER-2012-044; CERN-PH-EP-2013-005; LHCB-PAPER-2012-044.-
Geneva : CERN, 2013 - 17 p.
- Published in : J. Phys. G 40 (2013) 045001
IOP Open Access article: PDF; Related data file(s): ZIP; External link: Preprint
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10.
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Measurement of relative branching fractions of B decays to $\psi(2S)$ and $J/\psi$ mesons
/ LHCb collaboration
The relative rates of B-meson decays into $J/\psi$ and $\psi(2S)$ mesons are measured for the three decay modes in pp collisions recorded with the LHCb detector. The ratios of branching fractions ($\mathcal{B}$) are measured to be \begin{equation*} \begin{array}{lll} \frac{\mathcal{B}( B^+ \to \psi(2S) K^+)}{\mathcal{B}( B^+ \to J/\psi K^+ )} &=& 0.594 \pm 0.006 (stat) \pm 0.016 (syst) \pm 0.015\,(R_{\psi}), \\ \frac{\mathcal{B}( B^0 \to \psi(2S) K^{*0})}{\mathcal{B}( B^0 \to J/\psi K^{*0})} &=& 0.476 \pm 0.014 (stat) \pm 0.010 (syst) \pm 0.012\,(R_{\psi}), \\ \frac{\mathcal{B}^{0}_{s}( B^0_s \to \psi(2S)\phi)}{\mathcal{B}( B^0_s \to J/\psi\phi)} &=& 0.489 \pm 0.026 (stat) \pm 0.021 (syst) \pm 0.012\,(R_{\psi}), \end{array} \end{equation*} where the third uncertainty is from the ratio of the $\psi(2S)$ and $J/\psi$ branching fractions to $\mu\mu$..
arXiv:1205.0918; CERN-PH-EP-2012-113; LHCB-PAPER-2012-010; CERN-PH-EP-2012-113; LHCB-PAPER-2012-010.-
2012-08-29 - 14 p.
- Published in : Eur. Phys. J. C 72 (2012) 2118
Fulltext: PDF; Related data file(s): ZIP; Springer Open Access article: PDF; External link: Preprint
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